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- /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*- */
- /* ***** BEGIN LICENSE BLOCK *****
- * Version: MPL 1.1/GPL 2.0/LGPL 2.1
- *
- * The contents of this file are subject to the Mozilla Public License Version
- * 1.1 (the "License"); you may not use this file except in compliance with
- * the License. You may obtain a copy of the License at
- * http://www.mozilla.org/MPL/
- *
- * Software distributed under the License is distributed on an "AS IS" basis,
- * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
- * for the specific language governing rights and limitations under the
- * License.
- *
- * The Original Code is Mozilla FastLoad code.
- *
- * The Initial Developer of the Original Code is
- * Netscape Communications Corporation.
- * Portions created by the Initial Developer are Copyright (C) 2001
- * the Initial Developer. All Rights Reserved.
- *
- * Contributor(s):
- * Brendan Eich <brendan@mozilla.org> (original author)
- *
- * Alternatively, the contents of this file may be used under the terms of
- * either of the GNU General Public License Version 2 or later (the "GPL"),
- * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
- * in which case the provisions of the GPL or the LGPL are applicable instead
- * of those above. If you wish to allow use of your version of this file only
- * under the terms of either the GPL or the LGPL, and not to allow others to
- * use your version of this file under the terms of the MPL, indicate your
- * decision by deleting the provisions above and replace them with the notice
- * and other provisions required by the GPL or the LGPL. If you do not delete
- * the provisions above, a recipient may use your version of this file under
- * the terms of any one of the MPL, the GPL or the LGPL.
- *
- * ***** END LICENSE BLOCK ***** */
-
- #include "nsISupports.idl"
- #include "nsrootidl.idl"
-
- /**
- * An interface for access to a buffering stream implementation's underlying
- * memory buffer.
- *
- * Stream implementations that QueryInterface to nsIStreamBufferAccess must
- * ensure that all buffers are aligned on the most restrictive type size for
- * the current architecture (e.g., sizeof(double) for RISCy CPUs). malloc(3)
- * satisfies this requirement.
- */
- [uuid(ac923b72-ac87-4892-ac7a-ca385d429435)]
- interface nsIStreamBufferAccess : nsISupports
- {
- /**
- * Get access to a contiguous, aligned run of bytes in the stream's buffer.
- * Exactly one successful getBuffer call must occur before a putBuffer call
- * taking the non-null pointer returned by the successful getBuffer.
- *
- * The run of bytes are the next bytes (modulo alignment padding) to read
- * for an input stream, and the next bytes (modulo alignment padding) to
- * store before (eventually) writing buffered data to an output stream.
- * There can be space beyond this run of bytes in the buffer for further
- * accesses before the fill or flush point is reached.
- *
- * @param aLength
- * Count of contiguous bytes requested at the address A that satisfies
- * (A & aAlignMask) == 0 in the buffer, starting from the current stream
- * position, mapped to a buffer address B. The stream implementation
- * must pad from B to A by skipping bytes (if input stream) or storing
- * zero bytes (if output stream).
- *
- * @param aAlignMask
- * Bit-mask computed by subtracting 1 from the power-of-two alignment
- * modulus (e.g., 3 or sizeof(PRUint32)-1 for PRUint32 alignment).
- *
- * @return
- * The aligned pointer to aLength bytes in the buffer, or null if the
- * buffer has no room for aLength bytes starting at the next address A
- * after the current position that satisfies (A & aAlignMask) == 0.
- */
- [notxpcom] charPtr getBuffer(in PRUint32 aLength, in PRUint32 aAlignMask);
-
- /**
- * Relinquish access to the stream's buffer, filling if at end of an input
- * buffer, flushing if completing an output buffer. After a getBuffer call
- * that returns non-null, putBuffer must be called.
- *
- * @param aBuffer
- * A non-null pointer returned by getBuffer on the same stream buffer
- * access object.
- *
- * @param aLength
- * The same count of contiguous bytes passed to the getBuffer call that
- * returned aBuffer.
- */
- [notxpcom] void putBuffer(in charPtr aBuffer, in PRUint32 aLength);
-
- /**
- * Disable and enable buffering on the stream implementing this interface.
- * DisableBuffering flushes an output stream's buffer, and invalidates an
- * input stream's buffer.
- */
- void disableBuffering();
- void enableBuffering();
-
- /**
- * The underlying, unbuffered input or output stream.
- */
- readonly attribute nsISupports unbufferedStream;
- };
-
- %{C++
-
- // Swap macros, used to convert to/from canonical (big-endian) format
- #if defined IS_LITTLE_ENDIAN
-
- # define NS_SWAP16(x) ((((x) & 0xff) << 8) | (((x) >> 8) & 0xff))
- # define NS_SWAP32(x) ((NS_SWAP16((x) & 0xffff) << 16) | (NS_SWAP16((x) >> 16)))
-
- // We want to avoid casting to 32-bit types if possible, since that violates
- // aliasing rules (a standard compiler may assume that pointers of two types
- // do not address overlapping storage).
- //
- // XXX What if we have a compiler that follows aliasing rules strictly but
- // doesn't have a 64-bit int type?
- //
- // XXXbe shouldn't NSPR's LL_INIT work for non-constant arguments in all cases?
-
- # if defined HAVE_LONG_LONG
- # if PR_BYTES_PER_LONG == 8
- # define ULL_(x) x ## UL
- # elif (defined WIN32 || defined WIN16) && !defined __GNUC__
- # define ULL_(x) ((uint64) x ## i64)
- # else
- # define ULL_(x) x ## ULL
- # endif
-
- # define NS_SWAP64(x) ((((x) & ULL_(0xff00000000000000)) >> 56) | \
- (((x) & ULL_(0x00ff000000000000)) >> 40) | \
- (((x) & ULL_(0x0000ff0000000000)) >> 24) | \
- (((x) & ULL_(0x000000ff00000000)) >> 8) | \
- (((x) & ULL_(0x00000000ff000000)) << 8) | \
- (((x) & ULL_(0x0000000000ff0000)) << 24) | \
- (((x) & ULL_(0x000000000000ff00)) << 40) | \
- (((x) /* & ULL_(0x00000000000000ff) */) << 56))
- # else
- # define NS_SWAP64(x) LL_INIT((((x).lo /* & 0xff000000ul */) >> 24) | \
- (((x).lo & 0x00ff0000ul) >> 8) | \
- (((x).lo & 0x0000ff00ul) << 8) | \
- (((x).lo /* & 0x000000fful */) << 24), \
- (((x).hi /* & 0xff000000ul */) >> 24) | \
- (((x).hi & 0x00ff0000ul) >> 8) | \
- (((x).hi & 0x0000ff00ul) << 8) | \
- (((x).hi /* & 0x000000fful */) << 24))
- # endif
-
- #elif defined IS_BIG_ENDIAN
-
- # define NS_SWAP16(x) (x)
- # define NS_SWAP32(x) (x)
- # define NS_SWAP64(x) (x)
-
- #else
-
- # error "Unknown byte order"
-
- #endif
-
- /**
- * These macros get and put a buffer given either an sba parameter that may
- * point to an object implementing nsIStreamBufferAccess, nsIObjectInputStream,
- * or nsIObjectOutputStream.
- */
- #define NS_GET_BUFFER(sba,n,a) ((sba)->GetBuffer(n, a))
- #define NS_PUT_BUFFER(sba,p,n) ((sba)->PutBuffer(p, n))
-
- #define NS_GET8(p) (*(PRUint8*)(p))
- #define NS_GET16(p) NS_SWAP16(*(PRUint16*)(p))
- #define NS_GET32(p) NS_SWAP32(*(PRUint32*)(p))
- #define NS_GET64(p) NS_SWAP64(*(PRUint64*)(p))
- #define NS_GET_FLOAT(p) ((float)NS_SWAP32(*(PRUint32*)(p)))
- #define NS_GET_DOUBLE(p) ((double)NS_SWAP64(*(PRUint64*)(p)))
-
- #define NS_PUT8(p,x) (*(PRUint8*)(p) = (x))
- #define NS_PUT16(p,x) (*(PRUint16*)(p) = NS_SWAP16(x))
- #define NS_PUT32(p,x) (*(PRUint32*)(p) = NS_SWAP32(x))
- #define NS_PUT64(p,x) (*(PRUint64*)(p) = NS_SWAP64(x))
- #define NS_PUT_FLOAT(p,x) (*(PRUint32*)(p) = NS_SWAP32(*(PRUint32*)&(x)))
- #define NS_PUT_DOUBLE(p,x) (*(PRUint64*)(p) = NS_SWAP64(*(PRUint64*)&(x)))
-
- %}
-